The Multi Input Multi Output (MIMO) technology is a significant breakthrough of the smart antenna technology in the field of wireless mobile communication. The MIMO technology can improve the communication system capacity and the spectrum efficiency exponentially without increasing the bandwidth, and it is the key technology applied to the new generation of mobile communication system. Both the transmitting end and the receiving end of the MIMO system are provided with a plurality of antennas. During the signal transmission, the transmitting end may transmit a plurality of independent signals through different transmitting antennas in a Spatial Multiplexing (SM) mode, while the receiving end may receive signals from different receiving antennas and acquire signals transmitted by the transmitting end from the received signals.
In the prior art, the transmitting ends only share their respective channel information. Then each transmitting end centralizes interferences from all other transmitting ends to the signal spaces that can be processed by corresponding receiving ends in an Interference Alignment (IA) method based on a principle of maximizing the Signal-to-Interference and Noise Ratio (SINR) at the receiving end and a principle of maximizing the Signal-to-Leakage and Noise Ratio (SLNR) at the transmitting end.
The prior art has the following deficiency:
In the prior art, each transmitting end centralizes the interferences from all other transmitting ends to the signal spaces that can be processed by corresponding receiving ends based on the principles of SINR and SLNR maximization, and can not completely eliminating interferences. As a result, when the Signal to Noise Ratio (SNR) is lowered to a certain degree such as 40 dB or 50 dB, the Bit Error Rate (BER) is no longer reduced along with the decrease of the SNR, and a BER floor occurs.